Near Death - About the Continuity of Consciousness

Presentation given at the Conference for Consciousness Studies, Arizona.

Pim van Lommel, Cardiologist.17-3-2003

(Near Death Experiences)

I would like first to talk about our recently published study in the Lancet, entitled: "Near death experience in survivors of cardiac arrest, a prospective study in the Netherlands". And after that I would like to talk about its implications for consciousness studies, and discuss how it could be possible to explain the continuity of our consciousness.

In my view the only possible empirical approach to evaluate theories about consciousness is research on NDE, because in studying the several universal elements that are reported during NDE, we get the opportunity to verify all the existing theories about consciousness that have been discussed until now.

But first I want to think about death, and what it means to us. As a cardiologist I am frequently confronted with death and dying, and the fear and uncertainty of patients and their family. The confrontation with death raises many basic questions, also with physicians. Death is still taboo in our western world. Why are we afraid of death? Are we right with our concepts about death? Most of us believe that death is the end of our existence; we believe that it is the end of everything we are. We believe that the death of our body is the end of our identity, the end of our thoughts and memories, that it is the end of our consciousness. Do we have to change our concepts about death, not only based on what has been thought and written about death in human history around the world in many cultures, in many religions, and in all times? But also to change our concepts about death based on insights from recent scientific research on NDE?

What happens when I am dead? What is death? During our life 500.000 cells die each second, each day die about 50 billion cells in our body, resulting in a new body each year. So cell death is totally different from body death when you eventually die. During your life your body changes continuously, each day, each minute, each second. But no one realizes this permanent change. And from where comes the continuity of our permanent changing body? Cells are just the building stones of our body, like the bricks of a house, but who is the architect, who coordinates the building of this house? Each year about 98% of our molecules and atoms in our body have been replaced.

Each year a new body has been build, a new house has been build, but who was the architect? Compare our body with a car: when parked somewhere it is not capable to do anything, but as soon as the driver is in the car, and energy is available (fuel), the car, which is only matter, can drive and speed up. The driver decides and coordinates the performance of the car. Also the body needs a conductor. A human person must be more than just his body. When you have died, only mortal remains are left. But where is the conductor of the body? Is someone his body, or do we have a body?

What about our consciousness when we die?-Where am I during most of the night when I am sleeping, and what kind of consciousness do I have during my dreams? -Is there still consciousness when someone is in coma? Recently a book was published in the Netherlands, titled: "Return from coma". Following a very severe traffic accident, the author was in a coma for three weeks, and she describes in detail what she experienced during her coma, like out-of-body states, being in another dimension, but also seeing and hearing the nurses and doctors in the ICU. She was not capable to let them know that she was conscious of what was going on in her surroundings, and that she did not understand where she was, and why. Communication was impossible because of her coma.

-Is there still consciousness when someone is clinical dead during cardiac arrest?

-Is there still consciousness when someone has been declared to be brain dead by physicians, and the procedure of organ transplantation should be started?

-Is brain dead really means death, or is it just the beginning of the process of dying that can last for hours to days, and what happens to consciousness during this period?

In his book "My dreams during coma" a patient describes what he experienced during his period of brain death that was caused by complications following surgery for a brain tumour. His family refused to give permission for organ transplantation, and in retrospect he was very happy his family did so, because to the surprise of his neurologists he regained consciousness from his coma three weeks later! -And could there still be consciousness after someone really has died, when his body is cold?

Is it possible to get insight in the relationship between function of the brain and consciousness? In 1969 during my rotating internship a patient was successfully resuscitated in the cardiac ward by electrical defibrillation. Defibrillation was recently introduced those days, and coronary care units were started in hospitals because of this new CPR technique. The patient regained consciousness, and was very, very disappointed. He told me about a tunnel, beautiful colours, a light, and beautiful music. I have never forgotten this event, but I never did anything with it. I had not read about these kinds of experiences in 1969, "near-death experiences" which were first described scientifically in a retrospective study in 1976 by Raymond Moody, who became interested after hearing about this experience at the University.

George Ritchie told during a course of lectures what he had experienced during a period of clinical death of 6- minute duration as a complication of his pneumonia in 1943 during his medical study in the army.

In 1986, after the death of my 40-year old brother, I read his book "Return from Tomorrow", and out of curiosity and, to be honest, with some scepticism, I started to interview my out-patient clinic patients who had survived their cardiac arrest. But to my real surprise, patients reported to me within two years about fifty NDEs. And now my scientific curiosity started to grow. Because according to our current medical concepts it is not possible to experience consciousness during a period of cardiac arrest, during the period of unconsciousness that is named clinical death, when circulation and breathing have ceased.

A Near-Death Experience (NDE) seems to be a relatively regularly occurring, and to many physicians an inexplicable phenomenon and hence ignored result of survival in a critical medical situation. An NDE can be defined as the reported memory of the whole of impressions during a special state of consciousness, including a number of special elements such as out-of-body experience, pleasant feelings, seeing a tunnel, a light, deceased relatives, or a life review. Many circumstances are described during which NDEs are reported, such as cardiac arrest (clinical death), shock after loss of blood, traumatic brain injury or intra-cerebral haemorrhage, near-drowning or asphyxia, but also in serious diseases not immediately life-threatening. Similar experiences to near-death ones can occur during the terminal phase of illness, and are called deathbed visions. Furthermore, identical experiences, so-called "fear-death" experiences, are mainly reported after situations in which death seemed unavoidable like serious traffic or mountaineering accidents. The NDE is transformational,causing profound changes of life-insight and loss of the fear of death. These experiences are reported with increasing frequency because of improved survival rates of critical ill patients resulting from modern techniques of resuscitation. The content of the NDE and the subsequent process of transformation appear to be essentially similar all over the world, in all cultures and in all times. The subjective nature and absence of a frame of reference for this experience lead to individual, cultural, and religious factors determining the vocabulary used to describe and interpret the experience.

Several theories on the origin of NDE have been proposed. Some think the experience is caused by physiological changes in the brain such as brain cells dying as a result of cerebral anoxia. Other theories encompass a psychological reaction to approaching death or a combination of such reaction and anoxia.

But until now there was no prospective, meticulous and scientifically designed study done to explain the cause and content of the NDE. All studies had been retrospective and very selective with respect to patients, like the studies of Raymond Moody, Kenneth Ring, Michael Sabom, and Melvin Morse. In retrospective studies 5-30 years can elapse between occurrence of the experience and its investigation, which often prevents accurate assessment of medical and pharmacological factors.

We wanted to know if there could be a physiological, pharmacological, or psychological explanation why people experience consciousness during a period of clinical death. We studied patients who survived cardiac arrest, because this is a well-described life threatening medical situation, where patients will ultimately die if CPR is not started within 5 to 10 minutes because of irreversible damage of the brain. The definition of clinical death was used for the period of unconsciousness caused by anoxia of the brain due to the arrest of circulation and/or breathing that happens during ventricular fibrillation in patients with acute myocardial infarction.

So we started a prospective study in 1988, and included all consecutive patients who were successfully resuscitated in ten Dutch hospitals. We did a short standardised interview with sufficiently recovered patients within a few days of resuscitation, and asked whether they could remind the period of unconsciousness, and what they recalled. Within four years, we interviewed 344 consecutive survivors. And we performed a longitudinal study with taped interviews of all late survivors with NDE 2 years and 8 years following the cardiac arrest with a matched control group of survivors of cardiac arrest who did not report an NDE. This study was designed to assess if the transformation following an NDE is the result of having an NDE or the result of the cardiac arrest itself.

In this prospective study, we recorded the age, gender, religion, standard of education reached, whether the patient had previously heard of NDE, or had previously experienced NDE, whether CPR took place inside or outside the hospital, previous myocardial infarction, and how many times the patient had been resuscitated during his stay in hospital. We also asked them about fear before CPR. We estimated the duration of circulatory arrest and unconsciousness, and noted whether artificial respiration by intubation took place. We recorded the type and dose of drugs before, during and after the crisis, and assessed possible memory problems during the interview after lengthy or difficult resuscitation. We classified patients resuscitated after induced cardiac arrest during electrophysiologic stimulation (EPS) separately. In cases where memories were reported from the period of unconsciousness, we coded the experiences according to a weighted core experience index. In this system the depth of the NDE was measured according to the reported elements of the content of the NDE. The more elements were reported, the deeper the experience was and the higher the resulting score was.

Results: 62 patients (18%) reported some recollection of the time of clinical death. Of these patients 21 (6% of total) had a superficial NDE, and 41 (12%) had a core experience. 23 of the core group (7% of total) reported a deep or very deep experience. And 282 patients, i.e. 82%, had no recollection of the period of cardiac arrest.About 50 % of the patients with NDE reported the awareness of being dead, or had positive emotions, 30 % reported moving through a tunnel, had an observation of a celestial landscape, or had a meeting with deceased relatives. About 25 % of the patients with NDE had an out-of-body experience, had communication with "the light", or observed colours, 13% experienced a life review, and 8 % experienced a border.

Why only a small percentage of patients reported a NDE, while most did not? We found no influence on the frequency of NDE of the duration of cardiac arrest, or the duration of unconsciousness, or the need for intubation in complicated CPR or by induced cardiac arrest in EPS. Neither could we find any relationship between the frequency of NDE and given drugs, fear of death before the arrest, foreknowledge of NDE, religion or education. Increased frequency of NDE was reported by patients with age younger than 60 years, by patients with previous NDE, and by patients with more than one CPR during stay in hospital. Patients with loss of memory induced by lengthy CPR reported significant fewer NDE. Good short-term memory seems to be essential for remembering NDE. Surprisingly, we found that significantly more patients who had a NDE, especially a deep experience, died within 30 days of CPR.

In our follow-up research into transformational processes after NDE, we found a significant difference between the patients with NDE compared to those without this experience. Patients could recall their NDE almost exactly 2 and 8 years later. The process of transformation took several years to consolidate. Patients with NDE did not show any fear of death, they strongly believed in an afterlife, and their insight in what is important in life had changed: love and compassion for yourself, for others, and for nature. They understood now the cosmic law that everything you do to others will be ultimately returned to yourself; hatred and violence as well as love and compassion. Remarkably, there was often evidence of increased intuitive feelings. Furthermore, the long lasting transformational effects of an experience that lasts only a few minutes was a surprising and unexpected finding.

Several theories have been proposed to explain NDE. However, in our prospective study we did not show that psychological, physiological or pharmacological factors caused these experiences after cardiac arrest. With a purely physiological explanation such as cerebral anoxia for the experience, most patients who had been clinically dead should report a NDE. All 344 patients had been unconscious because of anoxia of the brain resulting from their cardiac arrest.

And yet, neurophysiological processes must play some part in NDE, because NDE-like experiences can be induced through electrical stimulation of some parts of the cortex in patients with epilepsy, with high carbon dioxide levels (hypercarbia), and in decreased cerebral perfusion resulting in local cerebral hypoxia, as in rapid acceleration during training of fighter pilots, or as in hyperventilation followed by valsalva manoeuvre. Ketamine-induced experiences resulting from blockage of the NMDA-receptor, and the role of endorphin, serotonin, and enkephalin have also been mentioned, as have near-death-like experiences after the use of LSD, or mushrooms (psilocybine and mescaline). These induced experiences can consist of unconsciousness, out-of-body experiences, and perception of sound, light or flashes of recollection from the past. These recollections, however, consist of fragmented and random memories unlike the panoramic life-review that can occur in NDE. Further, transformational processes with changing life-insight and disappearance of the fear of death are rarely reported after induced experiences. Thus, induced experiences are not identical to NDE.

Our question must be: Why only 18% of the survivors of cardiac arrest report a NDE?

With lack of evidence for any other theories for NDE, the thus far assumed, but never proven, concept that consciousness and memories are localised IN the brain should be discussed.

How could a clear consciousness outside one's body be experienced at the moment that the brain no longer functions during a period of clinical death, with flat EEG? Furthermore, blind people have also described veridical perceptions during out-of-body experiences at the time of their NDE. Another theory holds that NDE might be a changing state of consciousness (transcendence, or the theory of continuity), in which memories, identity, and cognition, with emotion, function independently from the unconscious body, and retain the possibility of non-sensory perception. And during NDE consciousness could also be experienced in a dimension without our conventional, body-linked concept of time and space. Scientific study of NDE pushes the limits of our medical and neurophysiological ideas about the range of consciousness and the mind-brain relation.

Before I go more deeply into some neurophysiological aspects of brain functioning during cardiac arrest, I would like to reconsider certain elements of the NDE, like the out-of-body experience, the holographic life review and preview, the encounter with deceased relatives, the return into the body and the disappearance of the fear of death.

The out-of-body experienceIn this experience people have veridical perceptions from a position out and above their lifeless body. NDEers have the feeling that they have apparently taken off their body like an old coat and to their surprise they appear to have retained their own identity with the possibility of perception with emotions and with a very clear consciousness. This out-of-body experience is scientifically important because doctors, nurses and relatives can verify the reported perceptions. This is the report of a nurse of a Coronary Care Unit:

"During night shift an ambulance brings in a 44-year old cyanotic, comatose man into the coronary care unit. He had been found about an hour before in a meadow by passers-by. After admission, he receives artificial respiration without intubation, while heart massage and defibrillation are also applied. When we want to intubate the patient, he turns out to have dentures in his mouth. I remove these upper dentures and put them onto the "crash car". Meanwhile, we continue extensive CPR. After about an hour and a half the patient has sufficient heart rhythm and blood pressure, but he is still ventilated and intubated, and he is still comatose. He is transferred to the intensive care unit to continue the necessary artificial respiration. Only after more than a week do I meet again with the patient, who is by now back on the cardiac ward. I distribute his medication.

The moment he sees me he says: "O, that nurse knows where my dentures are". I am very surprised. Then he elucidates:"Yes, you were there when I was brought into hospital and you took my dentures out of my mouth and put them onto that car, it had all these bottles on it and there was this sliding drawer underneath and there you put my teeth."

I was especially amazed because I remembered this happening while the man was in deep coma and in the process of CPR. When I asked further, it appeared the man had seen himself lying in bed, that he had perceived from above how nurses and doctors had been busy with the CPR.

He was also able to describe correctly and in detail the small room in which he had been resuscitated as well as the appearance of those present like myself. At the time that he observed the situation he had been very much afraid that we would stop CPR and that he would die. And it is true that we had been very negative about the patient's prognosis due to his very poor medical condition when admitted. The patient tells me that he desperately and unsuccessfully tried to make it clear to us that he was still alive and that we should continue CPR. He is deeply impressed by his experience and says he is no longer afraid of death. Four weeks later he left hospital as a healthy man.

The holographic life reviewDuring this life review the subject feels the presence and renewed experience of not only every act but also every thought from one's past life, and one realizes that all of it is an energy field which influences oneself as well as others. All that has been done and thought seems to be significant and stored. Insight is obtained about whether love was given or on the contrary withheld. Because one is connected with the memories, emotions and consciousness of another person, you experience the consequences of your own thoughts, words and actions to that other person at the very moment in the past that they occurred and in the way they were experienced by the other as well as by yourself at that time. Hence there is during a life review a connection with the fields of consciousness of other persons as well as with your own fields of consciousness (interconnectedness). And one inevitably understands the cosmic law that everything you give to others will be returned to yourself. If you hated someone during your life, you will receive hatred, if you used violence to someone you will receive violence, and if you gave love and compassion to others, you will feel love and compassion yourself. They survey their whole life in one glance; time and space do not seem to exist during such an experience. Instantaneously they are where they concentrate upon (non-locality), and patients can talk for hours about the content of the life review even though the resuscitation only took minutes.

Quotation:"All of my life up till the present seemed to be placed before me in a kind of panoramic, three-dimensional review and each event seemed to be accompanied by a consciousness of good or evil or with an insight in cause or effect. Not only did I perceive everything from my own viewpoint, but I also knew the thoughts of everyone involved in the event, as if I had their thoughts within me. This meant that I did not only perceive what I had done or thought, but even in what way it had influenced others, as if I saw things with all-seeing eyes. And so even your thoughts are apparently not wiped out. And all the time during the review the importance of love was emphasised. Looking back, I cannot say how long this life review and life insight lasted, it may have been long, for every subject came up, but at the same time it seemed just a fraction of a second, because I perceived it all at the same moment. Time and distance seemed not to exist. I was in all places at the same time, and sometimes my attention was drawn to something, and then I would be present there."

The PreviewAlso a preview can be experienced, in which both future images from personal life events (sometimes remembered only later in the shape of "déja vu") as well as more general images from the future occur, even though it must be stressed that these surveyed images should be considered purely as possibilities. And again it seems as if time and space do not exist during this review. Quotation:"I had a nice eye contact, they looked at me full of love, and then I surveyed a great part of my life to come; the care for my children, the terminal illness of my wife, the circumstances I would be mixed up with, in my job and besides. I surveyed it completely. And then I got the feeling that I had to decide now: "I may stay here, or I have to go back", but I had to decide now".

3) The encounter with deceased relatives.If deceased acquaintances or relatives are encountered in an otherworldly dimension, they are usually recognised by their appearance, while communication is possible through thought transfer. Thus, during an NDE it is also possible to come into contact with fields of consciousness of deceased persons (interconnectedness). Sometimes persons are met whereas it was impossible to know that they had died, sometimes persons unknown to them are encountered during an NDE.

Quotation: "During my cardiac arrest I had a extensive experience () and later I saw, apart from my deceased grandmother, a man who had looked at me lovingly, but whom I did not know. More than 10 years later, at my mother's deathbed, she confessed me that I had been born out of an extramarital relationship, my father being a Jewish man who had been deported and killed during the second World War, and my mother showed me his picture. The unknown man that I had seen more than 10 years before during my NDE turned out to be my biological father."

4) The return into the bodySome patients can describe how they returned into their body, mostly through the top of the head, after they had come to understand through wordless communication with a Being of Light or a deceased relative that "it wasn't their time yet" or that "they still had a task to fulfil". The conscious return into the body is experienced as something very oppressive. They regain consciousness in their body and realize that they are "locked up" in their body, meaning again all the pain and restriction by their disease. They also realize that a part of their consciousness with deep knowledge and understanding as well as the feeling of unconditional love and acceptance have been taken away from them again.

Quotation:"And when I regained consciousness in my body, it was so terrible, so terriblethat experience was so beautiful, I never would have liked to come back, I wanted to stay there..and still I came back. And from that moment on it was a very difficult experience to live my life again in my body, with all the limitations I felt in that period."

5)The disappearance of fear of deathNearly all people who have experienced an NDE have lost their fear of death. This is due to the realization that there is a continuation of consciousness, even when you have been declared dead by bystanders or even by doctors. You are separated from the lifeless body, retaining the ability of perception, while you also can experience consciousness in a timeless dimension where deceased persons can be encountered.

Quotation:"It is outside my domain to discuss something that can only be proven by death. For me, however, the experience was decisive in convincing me that consciousness lives on beyond the grave. Death was not death, but another form of life."

Another quotation:"This experience is a blessing for me, for now I know for sure that body and mind are separated, and that there is life after death."

Following an NDE people know of the continuity of their consciousness, retaining all thoughts and past events. And this insight causes exactly their process of transformation, and the loss of fear of death. Man appears to be more than just a body.

All these elements of an NDE were experienced during the period of cardiac arrest, during the period of unconsciousness, during the period of clinical death! But how is it possible to explain these experiences during the period of temporary loss of all functions of the brain due to acute pancerebral ischemia?

Complete cessation of cerebral circulation is found in induced cardiac arrest during threshold testing at implantation of internal defibrillators, indicated for life-threatening rhythm disturbances. This complete cerebral ischemic model can be usedto study the result of anoxia of the brain. During induced ventricular fibrillation(VF) complete circulatory arrest occurs, with complete cessation of cerebral flow. The Vmca, the middle cerebral artery blood flow, which is a reliable trend monitor of the cerebral blood flow, decreases to 0 cm/sec immediately after the induction of VF. Through many studies during induced cardiac arrest with constant registration of the EEG (and also in animal models), cerebral function has been shown to be severely compromised and electric activity in both the cerebral cortex and the deeper structures of the brain has been shown to be absent after a very short period of time.

During monitoring of the electric activity of the cortex, the first ischemic changes are shown at an average of 6.5 seconds following cardiac arrest, and they consist of a decrease of fast high amplitude waves and an increase of slow delta waves, and sometimes also an increase in amplitude of theta activity. Also initial slowing (attenuation) of the EEG waves may be the first sign of cerebral ischemia. With prolongation of the cerebral ischemia ultimately a declining to isoelectricity (a flat line) is always monitored within 10 to 20 (mean 15) seconds from the onset of the cardiac arrest.

Clinical investigation during cardiac arrest not only shows us functional loss of the cortex with unconsciousness and areflexia of the body, but also the abolition of the brainstem activity is observed by the loss of the cornea-reflex, of the gag-reflex, and later also by the finding of fixed dilated pupils. And respiration has ceased because of anoxia of the medulla oblongata. In those cases where the duration of cardiac arrest exceeds 37 seconds, the EEG activity may not return for minutes to many hours, depending of the duration of cardiac arrest, in spite of the maintenance of adequate blood pressure during the recovery phase after restoration of cardiac rhythm. This is caused by the initial overshoot on reperfusion (hyperoxia), which is always followed by a significant decrease in cerebral blood flow brought on by cerebral oedema, resulting in reduced cerebral oxygen uptake.

In acute myocardial infarction, the duration of cardiac arrest on the CCU is usually 60-120 seconds, on the cardiac ward 2-5 minutes, and in out-of-hospital arrest it usually exceeds 5-10 minutes. Only during threshold testing of internal defibrillators or during electro physiologic stimulation studies will the duration of cardiac arrest hardly exceed 30-60 seconds.

We have to come to the conclusion that all experiences with clear consciousness, as told by the patients in our study, must have taken place during a flat line EEG, during transient loss of all functions of the brain.

Anoxia causes loss of function of our cell systems. However, in anoxia of only a few minutes duration, this loss may be transient, while in prolonged anoxia cell death occurs with permanent functional loss. During an embolic event, a small clot obstructs the blood flow in a small vessel of the cortex, resulting in anoxia of that part of the brain with loss of electrical activity. This results in a functional loss of the cortex like hemiplegia or aphasia. When the clot is resolved or broken down within several minutes the lost cortical function is restored. This is called a transient ischemic attack (TIA). However, when the clot obstructs the cerebral vessel for minutes to hours it will result in neuronal cell death with a permanent loss of function of this part of the brain, with persistent hemiplegia or aphasia, and the diagnosis of cerebro vascular accident (CVA) is made.

So transient anoxia results in transient loss of functions.In cardiac arrest, global anoxia of the brain occurs within seconds. Timely and adequate CPR reverses this functional loss of the brain because definitive damage of the brain cells, resulting in cell death, has been prevented. Long lasting anoxia, caused by cessation of blood flow to the brain for more than 5-10 minutes, results in irreversible damage and extensive cell death in the brain. This is called brain death, and most patients will ultimately die.

How could a clear consciousness outside one's body be experienced at the moment that the brain no longer functions during a period of clinical death, with flat EEG? Up to the present, it has generally been assumed that consciousness and memories are localized inside the brain, that the brain produces them. As long as this never proven concept is maintained, this means that together with physical death, and also in clinical death and during brain death, our consciousness and memories must pass away. However, as is stated before, during an NDE, people experience the continuity of their consciousness, retaining all thoughts and past events from early childhood, with cognitive functions, with emotions, with self identity, and with the possibility of perception out and above one's lifeless body. Consciousness can be experienced in another dimension without our conventional body-linked concept of time and space, where all past, present and future events exist and can be observed simultaneously and instantaneously (non-locality). In the other dimension, one can be connected with the personal memories and the fields of consciousness of yourself as well as of others, as well as with the fields of consciousness of deceased relatives (universal interconnectedness). And the conscious return into one's body can be experienced, together with the feeling of bodily limitation, and sometimes also the awareness of the loss of universal wisdom and love they had experienced during their NDE.

NeurophysiologyFor decades, extensive research has been done to localize consciousness and memories inside the brain, so far without success. In connection with the never proven concept that consciousness and memories are produced and stored inside the brain, we should ask ourselves how a non-material activity such as concentrated attention or thinking can correspond with a visible (material) reaction in the form of a measurable electrical, magnetic and chemical activity at a certain place in the brain. Neuro-physiological studies have shown these activities through EEG, magneto-encephalogram (MEG) and at present also through magnetic resonance imaging (MRI) and positron emission tomography (PET-scan). Surprisingly even an increase in cerebral blood flow is observed during such a non-material activity like thinking. And phenomena like presentiment, or the anomalous anticipatory brain activation, and also the so-called delay-and-antedating hypothesis of Benjamin Libet are a challenge to our current neuro-physiological theories.

The brain contains about 100 billion neurons, 20 billion of which are situated in the cerebral cortex. Several thousand neurons die each day, and there is a continuous renewal of the proteins and lipids constituting cellular membranes on a time-span basis ranging from several days to a few weeks. During life the cerebral cortex continuously adapts and thus modifies its neuronal network, also by changing the amount and location of synapses. All neurons show an electrical potential across their cell membranes, and each neuron has tens to hundreds of synapses that influence other neurons. Transportation of information along neurons happens by means of action potentials, differences in membrane potential caused by synaptic depolarisation (excitatory effect) and hyperpolarisation (inhibitory effect). The sum total of changes along neurons causes transient electric fields and therefore also transient magnetic fields along the synchronously activated dendrites.

During each cerebral activity, these electrical and magnetic patterns of the 100 billion neurons, based on photons, change each nanosecond. Not the number of neurons, the precise shape of the dendrites, nor the accurate position of synapses, neither the firing of individual neurons is crucial, but the derivative, the fleeting electric and/or magnetic fields generated along the dendrites. These should be shaped as optimally as possible into short-lasting meaningful patterns, constantly changing in four-dimensional shape and intensity by so-called self-organization, which can be considered as a biological quantum coherence phenomenon.

The neurons' electric and/or magnetic fields presumably consist of "virtual" photons. Virtual photons have no mass, being continuously generated and absorbed by all existing matter, and they have a measurable amount of energy, a nanonewton, or the so-called Casimir effect. They receive, by definition, insufficient energy to start an independent life as real photons, and they possess an electrical aspect and a magnetic aspect. The term virtual photon is used in quantum mechanics as a metaphor for the mathematical construction of electrical and magnetic fields. Virtual photons are always omnipresent in the universe, even in the deepest isolated vacuum in space where hardly any matter remains. And it should be kept in mind that also in all sub-molecular matter in the cells of our body, and also our brain, about 99.99% is "empty space", and that this void is "filled" with information-carrying waves such as electromagnetic fields from real photons, as well as fields from virtual photons.

Neurophysiological research is being performed using transcranial magnetic stimulation (TMS), in the course of which localized magnetic fields (real photons) are produced. TMS can excite or inhibit different parts of the brain, allowing functional mapping of cortical regions, and it can create transient functional lesions. In studies, TMS can interfere with visual and motion perception and give an interruption of cortical processing with an interval of 80-100 milliseconds. Also TMS can alter the functioning of the brain beyond the time of stimulation, but it does not appear to leave any lasting effect. Also by localized electrical stimulation of the temporal lobe during surgery for epilepsy, the neurosurgeon Penfield could sometimes induce flashes of recollection of the past (never a complete life review), experiences of light, sound or music, and rarely a kind of out-of-body experience. These experiences did not produce any transformation. Olaf Blanke also recently described in the journal Nature a patient with induced OBE by inhibition of cortical activity caused by electrical stimulation. From these observations, we have to conclude that localized artificial stimulation with real photons inhibit and disturb the constant changing electrical and magnetic fields of our neuronal networks, and so can influence and inhibit the normal function of our brain.

After many years of research both the Nobel Prize winners Wilder Penfield and John Eccles finally reached the conclusion that it is not possible to localize memories or consciousness inside the brain.

Could consciousness and memories be the product or the result of these constantly changing fields of virtual photons? Could these virtual photons be the elementary carriers of consciousness? Scientific research is done trying to create artificial intelligence by computer technology, which should be able to emulate programs evoking consciousness. But Roger Penrose, a quantum physicist, argues that algorithmic computations cannot emulate mathematical reasoning. The brain, as a closed system capable of internal and consistent computations, is insufficient to elicit human consciousness.

He uses a quantum mechanical approach to explain the relation between consciousness and the brain. He suggests that our inner reality which gives rise to our consciousness cannot be located in the brain, which would only actualise our subjective reality, but not define it. And Simon Berkovitch, a professor in Computer Science of the George Washington University, has calculated that the brain has an absolute inadequate capacity to produce and store all the informational processes of all our memories with associative thoughts in our brain. We should need 10 to the 24th operations per second, which is absolutely impossible for our neurons, each of which can transmit up to 100 signals per second. Also transfer rates of information far superior to the speed of light should be required. Others have calculated that we need more than 10 to the 45th bits memory capacity in our brain to store all the information of one person during his life, which is an incredible number. Also Herms Romijn, a Dutch neurobiologist, has stated that storage of all memories in the brain is anatomically and functionally impossible.

We have to conclude that the brain has not enough computing capacity to store all the memories with associative thoughts from one's life, has not enough retrieval abilities, and is not able to emulate consciousness.

And how then should we explain that consciousness and memories from early childhood can be experienced during a period of a non-functioning brain, during anoxia of the cortex and the brainstem, during isoelectricity or a flat line EEG?

We have to come to the conclusion, like Eccles, Penrose, Berkovitch, Romijn, and many others, that quantum mechanical processes should be the only explanation how consciousness and memories relate with the brain and the body during normal daily activities as well as during the period of brain death or clinical death.

I would like now to discuss some aspects of quantum physics, because this seems necessary to understand my concept of the continuity of consciousness I want to talk about. Quantum physics has completely overturned the existing view of our material, visible world. It tells us that particles can propagate like waves, and so can be described by a quantum mechanical wave function. As an immediate consequence, a particle can be in two or more states at the same time, a so-called superposition of states. It can be proven that light in some experiments behaves like particles (photons), and in some it behaves like waves, and both experiments are true. It appears that no observation is possible without fundamentally changing the observed subject. So in quantum physics, there is no objectivity; exactly like in studies on NDE and on consciousness, only subjectivity remains.

Everything influences everything in reciprocity, and the observer influences the outcome of an observed event. And at the same moment that an actual, local event takes place, it is instantaneously influenced by events at a great distance (non-local interconnectedness, or entanglement). This happens because all events are interrelated and are influencing each other. While observing, a probability is instantly changed into an actuality by collapse of the wave function.

Roger Penrose called this collapse, this resolution of multiple possibilities into one definitive state, objective reduction (O.R.), which could be based on quantum gravity. Elaborating on Bell's theorem, physicist David Bohm states that everything is constantly changing and moving in continuous interaction and that all shapes and events in the material universe (matter, space and time) are present (unfolded) in an implicate order of total wholeness and undivided unity. Time and space are not relevant in this submanifest universe, consisting only of fields of probability.

The whole, self-organizing course of the universe, extending over the past, present and future, is in its relevant time-space configuration, permanently present in this phase-space. Within this phase-space, which is a causal world of precise mathematical exactitude, no matter is present, everything belongs to uncertainty and possibilities, and neither measurements nor observations are possible by physicists, but this phase-space can be influenced from outside. The phase-speed in this invisible and non-measurable phase-space dimension varies from speed of light to infinity, while the speed of particles in our visible, physical time-space varies from zero to the speed of light. Everything in our visible material world with time and space is based on continuous interaction and succession of quantum states within this invisible phase-space.

Everything visible emanates from the invisible.

Our brain constructs in a mathematical way the so-called objective reality by interpretation of frequencies from 4-dimensional self-organizing patterns of virtual photons, and these virtual photons are projections from the phase-space, where everything from past, present and future is present as potential possibilities. According to Stuart Hameroff and Roger Penrose cytoskeletal microtubules in neurons may process information due to these self-organizing patterns, giving rise to coherent states, and with couplings between microtubules and membrane activities.

Our consciousness with declarative memories finds its origin in, and is stored in, this phase-space, and the cortex only serves as a relay station of memories and consciousness to receive them into our waking consciousness. But they do not physically occur!

Experiencing an NDE during clinical death, during a non-functional brain with flat EEG, one can consciously experience all past events during review as well as future events during preview at the same moment, since time and space do not exist.

In trying to understand this concept of quantum mechanical mutual interaction between the invisible phase-space and our visible, material body, it seems appropriate to compare it with modern worldwide communication. There is a continuous exchange of objective information by means of electromagnetic fields (real photons) for radio, TV, mobile telephone, or laptop computer. We are unaware of the innumerable amounts of electromagnetic fields that constantly, day and night, exist around us and through us as well as through structures like walls and buildings. We only become aware of these electromagnetic informational fields at the moment we use our mobile telephone or by switching on our radio, TV or laptop.

What we receive is not inside the instrument, nor in the components, but, thanks to the receiver, the information from the electromagnetic fields becomes observable to our senses and hence perception occurs in our consciousness. The voice we hear in our telephone is not inside the telephone. The concert we hear in our radio is transmitted to our radio. The images and music we hear and see on TV is transmitted to our TV set. The internet is not located inside our laptop. We can receive at about the same time what is transmitted with the speed of light from a distance of some hundreds or thousands of miles. And if we switch off the TV set, the reception disappears, but the transmission continues. The information transmitted remains present within the electromagnetic fields. The connection has been interrupted, but it has not vanished and can still be received elsewhere by using another TV set. Again, we do not realize the thousands of telephone calls, the hundreds of radio and TV transmissions, as well as the internet, coded as electromagnetic fields, that exist around us and through us.

Could our brain be compared with the TV set which receives electromagnetic waves (photons) and transforms them into image and sound, as well as with the TV camera which transforms image and sound into electromagnetic waves (photons)?

This electromagnetic radiation holds the essence of all information, but is only conceivable to our senses by suited instruments like camera and TV set.

The informational fields of our consciousness and of our memories, both evolving during our lifetime by our experiences and by the informational input from our sense organs, are present around us as electrical and/or magnetic fields (virtual photons), and these fields only become available to our waking consciousness through our functioning brain and other cells of our body.

So we need a functioning brain to receive our primary consciousness into our waking consciousness. And as soon as the function of the brain has been lost, like in clinical death or in brain death, with isoelectricity on the EEG, memories and consciousness do still exist, but the reception ability is lost. We can experience our consciousness outside our body, with the possibility of perception out and above our body, with identity, and with heightened awareness, attention, well-structured thought processes, memories and emotions. And we can experience our consciousness in a dimension where past, present and future exist at the same moment, without time and space, and our consciousness can be experienced as soon as attention has been directed to it. Everything happens according to our free will, and free choice. And later, people who experience NDE can experience their return into their body.

And how can we understand this interaction between our consciousness and our brain in our continuous changing body? As stated before, during our life the composition of our body changes continuously, as during each second, 500.000 cells die in our body. And from where comes the continuity of our permanent changing body? Cells and molecules are just the building stones.

In assessing all the theories mentioned above, it seems inevitable to consider the DNA in our cells as the place of resonance, or the interface, from where a constant exchange takes place, of a continuously changing mutual stream of information between our material body and a non-material universe, the phase-space, where everything is available as a possibility.

DNA is a protein molecule with a double helix structure. It is integrated in 23 pairs of chromosomes, defines 30.000 genes, and contains about 3 billion base pairs. The human genome differs only of 300 genes (1%) from the DNA of the mouse, but the main difference is that these animals have 10% less base pairs, and they hardly possess junk-DNA. About 95% of our human DNA has until now an unknown function, and because of this fact it is called junk-DNA or non-protein coding DNA. Presumably this junk DNA has an identifying purpose, to be compared with a kind of "barcode" functionality. DNA plays a central role in the forming and functioning of all body cells including nerve cells, and thus indirectly in generating their permanent changing electric and/or magnetic fields.

Human DNA is specific for each person on earth, it is the only permanent aspect of all cells from conception until death, and is not broken down. All 100 trillion cells in our body, with the nearly endless differentiation and specialization of functions, emerge from the one DNA-molecule that comes into being at the moment of conception. Everything the body can perform originates from the nearly endless possibilities contained in this first molecule of a new human being. It seems inevitably to conclude that DNA must be the originator of the continuity in our permanent changing body.

DNA itself does not contain the hereditary material, but is capable to receive the transmittable possibilities and memories from the past, as well as the so-called morphogenetic information, also part of the fields of our consciousness, because during our life the body, in all its differentiation, is continuously formed and rebuild from the moment of conception by the DNA in our cells. And in reciprocity DNA adds all our new experiences in the physical world into the fields of our consciousness. Personal specific DNA is the receiver as well as the transmitter of our permanently evolving personal consciousness.

According to Erwin Schrödinger, a quantum physicist, the DNA is an a-periodic crystal, an a-statistic molecule. A-statistic processes originate from the phase-space, and so DNA can function as a quantum antenna with non-local communication. In this quantum computer model, the 3 billion base pairs should function as qubits (quantumbits), with quantum superposition of simultaneously zero and one. In a normal computer bits are or zero or one. The DNA should function as a SQUID, a superconductive quantum interference device. And also protein formation dynamics, as governed by quantum forces in DNA, could play a role in consciousness.

Following this concept, all cellular, molecular and submolecular processes are influenced and coordinated from the phase-space. Quantum memory exists as wave patterns, created by experiences from the past, and these waves interfere with the quantum system in our (brain) cells, with wave patterns created by experiences during our life, and by our sense organs. Once again, one can compare this concept with our computer; the more experienced you are, the more information you can receive from the internet into your laptop, but the material aspect of your computer is always the same, and the internet is not in your computer, but you receive it. And using your website you add new information to the internet by transmitting it from your laptop.

Our consciousness is a field of information, consisting of energy waves, and it originates from the phase-space. According to the law of thermodynamics, energy is indestructible. So consciousness must be indestructible, eternal and infinite. And also following this definition, it must be impossible to demonstrate consciousness in the physical world, because it is impossible to do measurements in the phase-space. But the effects of consciousness on the physical world are measurable by EEG, MEG, MRI and PETscan.

All molecules, including the DNA and all atoms in a human cell are not dead matter, but have vibrational activity, which could resonate with a electromagnetic radiation at 10 to the 11th Hz, as a result of biological quantum coherence phenomena. All matter, also in our body cells, is 99.9% emptiness, and this emptiness is filled with energy waves and informational waves with co-resonance and interference patterns between our molecules.

This is like our surrounding "empty" material universe, which is permeated with invisible waves and energy. Each cell is connected with the penetrating waves of consciousness, and they communicate with each other, directly by electrical and magnetic waves, especially in our nervous system, and indirectly by neuropeptides, signal- and messenger proteins, hormones and antibodies. The direct informational exchange between cells must at least be close to the speed of light because of the reported turnover of 500.000 cells per second.

Following a heart transplant, the donor heart consists of DNA material foreign to the recipient. In the book: "Change of heart" it was described that sometimes the recipient experiences thoughts and feelings that are totally strange and new, and later it is obvious that they seem to fit with the character and consciousness of the deceased donor. The DNA in the donor heart gives rise to fields of consciousness that are to be received by the organ recipient.

Following an NDE, most people often to their own amazement and confusion may experience an enhanced intuitive sensibility, like clairvoyance and clairaudience, or prognostication dreams. These so-called para-psychological phenomena seem to correspond with non-local quantum mechanical interconnectedness with fields of consciousness of other people, or even better: with the informational fields of the phase-space. In people with an NDE, the functional receiving capacity of the DNA has been permanently changed, possibly by changing the functionality of informational RNA.

During cardiac arrest, the functioning of the brain, and of other cells in our body, stops because of anoxia. The electric and/or magnetic fields of our neurons and other cells disappear, and the possibility of resonance, the interface, is interrupted. Consciousness and memories are experienced outside the body, with identity, cognitive functions, with emotions, and with the possibility of perception out and above the body. Consciousness can be experienced in a dimension without time and space, the so-called phase-space, where all past and future is enfolded, and where wisdom and unconditional Love can be experienced.

This occurs during a period of clinical death, during a flat line EEG, with a non-functioning cortex and brainstem. It also occurs during coma, and also during brain death.

Life is the energy that creates the possibility to receive the fields of consciousness into our physical body, into our waking consciousness. And a non-functioning brain has no possibility to receive these fields of consciousness because of the elimination of the electric and /or magnetic fields in the DNA in our cells.

During life, our consciousness has an aspect of waves as well as of particles, and there is a permanent interaction between these two aspects of consciousness. The particle aspect of consciousness can be measured by means of EEG, MEG, MRI, and PET scan. This particle aspect is the physical aspect of our consciousness in the material world, the time space, and it originates from the wave aspect of our consciousness from the phase space by collapse of the wave function. The wave aspect of our indestructible consciousness in the phase-space, with non-local interconnectedness, is by definition not measurable by physical means. When we die, our consciousness will no longer have an aspect of particles, but only an eternal aspect of waves. This concept is a complementary, and not a dualistic theory.

The functioning brain and other cell systems in our body are by means of the DNA the RECEIVER OF as well as the TRANSMITTER TO our consciousness, but they are NOT the PRODUCER!

Our opinion on death changes fundamentally because of the almost unavoidable conclusion that at the time of physical death, consciousness will continue to be experienced in another dimension, in an invisible and immaterial world, the phase-space, in which all past, present and future is enclosed.

According to our hypothesis, death cannot be the end of our existence, but is just the end of our physical aspects. There seems to be a continuity of our consciousness. Research on NDE cannot give us the irrefutable scientific proof of this conclusion, because people with NDE did not die, as they came back, but they all were very, very close to death, without a functioning brain. As I said before: NDE pushes us to the limits of medical and scientific ideas about the range of human consciousness and the so-called mind-brain relation. In the future, we would like to develop more details on our hypothesis, but most aspects of our concept seem to concur with the results of current scientific theories from neurophysiology, psychology, nanobiology, and quantum mechanics.

The conclusion that consciousness is experienced independently of brain function might well induce a huge change in the scientific paradigm in western medicine, and could have practical implications in actual medical and ethical problems such as the care for comatose or dying patients, euthanasia, abortion, and the removal of organs for transplantation from somebody during his dying process, still having a beating heart in a warm body, but with the diagnosis of brain death.

So finally we have to realize that death, like birth, presumably is a mere passing from one state of consciousness to another.

Finally, I would like to quote Plato: The temporary material body is the temporary carrier of our immortal soul. Or: Time does not exist in the immaterial world. Plato is convinced that in communication we have to use words, but that we also have to realise that this is a limiting factor to verbalize the essence; the true nature of things is principally concealed, and not revealed, by our words. And in spite of being aware of this limitation, I have tried to use words to talk about my concepts on the continuity of our consciousness.